1. Field of the Invention
The present invention relates to a hand-held drive-in tool for driving fastening elements in a workpiece that includes a guide, a drive-in ram for driving-in the fastening elements, a muzzle part having a drive-in channel defining a receiving space for a fastening element, a magazine projecting sidewise from the muzzle part and having a guide channel for the fastening elements, a transporting slide for displacing the fastening elements in the guide channel, and a transporting spring for biasing the transporting slide in a transporting direction for feeding a fastening element into the receiving space, the tool further including a safety device having a press-on member supported on the muzzle part.
2. Description of the Prior Art
Drive-in tool of the type described above can be driven with, e.g., solid, gaseous, or liquid fuels, with compressed air, or electrically. As an energy accumulator for the drive-in ram in electrically driven tools, e.g., a mechanical drive spring, which is preloaded by an electrically driven tensioning mechanism, is used.
German Publication DE 40 13 022 A1 describes a drive-in tool of the type described above. The drive-in tool includes an impact mechanism for driving in a fastening element, e.g., a nail and which is preloaded toward a muzzle by a drive spring. A positioning device for displacing the impact mechanism in a drive-in position includes an electric motor and a speed reducing mechanism. A rotational movement of the electric motor is transmitted by the speed reduction mechanism and a cooperating therewith tooth disc to a hammer body with a drive-in ram of the impact mechanism, in order to displace the hammer body against a biasing force of a drive spring from an initial position to a drive-in-ready position in which the impact mechanism is ready for effecting an impact process.
The displacement in the drive-in-ready position is effected only upon actuation of the actuation switch. A magazine for fastening elements projects at a right angle from a muzzle part. In the magazine, there is arranged a spring-biased slide with which fastening elements such as, e.g., nails are displaced in the direction of a guide for the drive-in ram of the hammer body. The drive-in tool further includes an adjusting member that has a press-on element which projects axially beyond the muzzle of the muzzle part in the initial position of the drive-in tool when the tool is not pressed against a workpiece. The adjusting element functions as a safety element that insures that the drive-in tool cannot be actuated when the drive-in tool is not pressed with its muzzle against a workpiece.
In the known drive-in tool, the feeding of a fastening element in the receptacle in the guide for the drive-in ram in the muzzle part is effected only then when the drive spring is preloaded after actuation of the actuation switch, and the drive-in ram is displaced away in the guide in the nuzzle part. The fastening element, which was brought in the receptacle of the guide by the transporting slide, lies in front, in the drive-in direction, of the drive-in ram and will be ejected from the guide by the drive-in ram which is accelerated toward the muzzle by the drive spring. With the drive-in tool having a high setting energy such as, e.g., drive-in tools with strong drive springs, it makes sense, because of the relatively long time necessary for preloading the drive spring, to initiate a setting process already upon pressing of the drive-in tool against the workpiece. However, the drawback of the known drive-in tool consists in that the drive spring must remain preloaded in case of interruption of the drive-in process because the drive-in ram cannot be displaced again in its initial position, without first ejecting of the fastening element.
The object of the present invention is to provide a drive-in tool of the type described above in which the drawback of the known tool is eliminated and a release of the drive spring of the drive-in ram is possible, without driving a fastening element out when the drive-in tool is not actuated and is lifted again off a constructional element or workpiece.